Grafts that aid in the healing of damaged bone are a relatively old technology that has undergone substantial growth in light of recent advances in medicine and biology. Improved understanding of osteoinductive and osteoconductive properties of certain materials has enabled the design of implants of ever-increasing efficacy. Recent examples include U.S. Pat. No. 7,045,141 to Merboth et al., entitled “Allograft Bone Composition Having a Gelatin Binder”; U.S. Pat. No. 6,808,585 to Boyce et al., entitled “Osteogenic Implant Derived From Bone”; U.S. Pat. No. 6,548,080 to Gertzman et al., entitled “Method for Partially Demineralized Cortical Bone Constructs”; and U.S. Pat. No. 6,776,800 to Boyer, II et al., entitled “Implants Formed with Demineralized Bone”. Absorbable Collagen Sponge (“ACS”), by Integra LifeSciences Corporation (Plainsboro, N.J.), and Mastergraft® Matrix, by Medtronic Sofamor Danek (Memphis, Tenn.), are specific examples of grafts currently available on the market.
Many of these implants do not provide any structural support at the implant site. Structural support ranges from the ability to resist the tendency for compression of the graft by local tissues (space maintenance) to the ability to be weight bearing. There exist numerous situations in which it is desirable to have an implant that both aids in the re-growth of the bone at the implant site while also providing structural support, which are so-called structural implants. However, not all structural implants have the properties, such as compression resistance, necessary for certain applications.
Accordingly, it is desirable to provide an osteoimplant that provides structural capabilities, yet which provides superior osteoinductive, osteoconductive and re-absorption properties.